proficiency test spil-1 (2018) - eurofins scientific...4 conclusion the quality control performed,...
TRANSCRIPT
Quality Documentation
May 2018
Proficiency test SPIL-1 (2018) Organic matter, phosphorus, chloride, sulphate and suspended matter in wastewater (effluent)
Proficiency test SPIL-1 (2018) Quality Documentation May 2018
Eurofins Miljø A/S Smedeskovvej 38 DK-8464 Galten Denmark Tlf: +45 7022 4266 e-mail: [email protected] Web: www.eurofins.dk
Client
Environmental laboratories
Client’s representative
Project
Proficiency test SPIL-1 (2018)
Project No
20404-81
Authors
Stine Ottsen
Date 2018-05-23
Approved by Peter Rerup
Quality Documentation Report SJN PRE 2018-05-23
Revision Description By Approved Date
Key words Analytical quality, assigned value, precision, trueness, homogeneity, stability, CODCr, BOD5 (w. ATU), BOD7 (w. ATU), NVOC/TOC, total phosphorus, chloride, sulphate, suspended matter, wastewater
Classification
Open
Internal
Proprietary
Distribution
DANAK Eurofins:
Stine Ottsen, Peter Rerup
CONTENTS
1 INTRODUCTION ........................................................................................................... 1
2 FEATURES OF THE PROFICIENCY TEST .................................................................. 2 2.1 Sample preparation ....................................................................................................... 2 2.2 Statistical analysis of participants’ data ......................................................................... 2 2.3 Assigned and spike value .............................................................................................. 2 2.3.1 Assigned and spike values ............................................................................................ 3 2.3.2 Test of spike values ...................................................................................................... 3 2.3.3 Test of assigned values ................................................................................................. 4
3 HOMOGENEITY AND STABILITY OF SAMPLES ......................................................... 5
4 CONCLUSION .............................................................................................................. 6
5 REFERENCES ............................................................................................................. 7
ANNEX A LIST OF PARTICIPANTS ..................................................................................... 9
ANNEX B SAMPLE PREPARATION .................................................................................. 11
ANNEX C CONTROL OF SPIKE VALUES ......................................................................... 13
ANNEX D CONTROL OF RECOVERY ............................................................................... 21
ANNEX E CONCENTRATION LEVEL ................................................................................ 29
ANNEX F HOMOGENEITY AND STABILITY ..................................................................... 30
1
1 INTRODUCTION
A proficiency test on the analysis of organic matter, phosphorus, chloride, sulphate and suspended matter in wastewater was conducted on 15 March 2018. The proficiency test was organised by Eurofins Miljø A/S.
The present report contains Eurofins’ documentation for the quality of the proficiency test. Results of the proficiency test including data from participating laboratories and statistical analysis of these data were issued in a report to all participants /1/ on 19 April 2018.
2
2 FEATURES OF THE PROFICIENCY TEST
Participants in the proficiency test were a total of 71 laboratories from Denmark, Ger-many, Norway and Sweden. A list of participants is shown in Appendix A.
The closing date for submission of results was 4 april 2018. All participants had submit-ted their results before the dead-line.
2.1 Sample preparation
The parameters covered in the proficiency test are listed in Table 2 as are the abbrevi-ations used in this report.
Six samples were dispatched for the proficiency test. The samples were sample pairs covering the parameters as described in Table 1. The matrix of the samples represent-ed wastewater, in this case effluent. Sample preparation is described in Appendix B.
Table 1 Samples in the proficiency test
Sample name Parameters A1/B1 BOD BOD5 w. ATU, BOD7 w. ATU A1/B1 COD/NVOC CODCr, NVOC/TOC A2/B2 TP, Cl, SO4
A3/B3 TSS
2.2 Statistical analysis of participants’ data
A split-level design was used. The data analysis was performed in accordance with ISO 5725: “Accuracy (trueness and precision) of measurement methods and results” (1994) /2/ and as described in detail in Spliid (1992) /3/. A short introduction to the sta-tistics and a list of symbols and abbreviations used is given in Eurofins document “Schedule for a proficiency test”, which is available at Eurofins’ home page /4/.
The statistical model used is based on the assumption that the variances for the two samples in a sample pair are identical. The assumption was tested (F-test, 95% confi-dence level) and the result was that the two variances may be assumed to be identical for all parameters.
2.3 Assigned and spike value
An overview of the concentrations in the samples (the assigned values) and the differ-ence in concentration between the two samples of a sample pair (spike value) are shown in Table 2 compared to the range of concentrations normally encountered in effluent. The table also gives the expanded uncertainty of the assigned values.
3
Table 2 Assigned and spike values..
Parameter Abbreviation Unit Typical Range
Assigned value
Uncertainty of assigned value
Spike value
CODCr CODCr mg/L O2 5-75 48 2.4 6 BOD5 (w. ATU) BOD5 w. ATU mg/L O2 2-6 *) - - BOD7 (w. ATU) BOD7 w. ATU mg/L O2 2-6 4.2 0.24 0.7 NVOC/TOC NVOC/TOC mg/L C 2-30 18.9 0.90 3.0 Total phosphorus TP mg/L P 0.2-2 1.14 0.022 0.22 Chloride Cl mg/L 50-700 130 2.7 22 Sulphate SO4 mg/L 20-200 72 2.2 10 Total suspended solids
TSS mg/L 20-100 36.2 0.37 7.5
*) Only three laboratories reported results for BOD5 w. ATU using a standardised method and therefore no assigned value is given.
2.3.1 Assigned and spike values The content of each parameter in each sample is given an assigned value for the sam-ple with the lower content and a spike value, the spike value being the difference in concentration between the two samples of the sample pair.
In order to ensure optimal use of the data, the assigned value is calculated as the av-erage of the median for both samples in the sample pair after subtraction of the spike value. The spike values are calculated from sample preparation except for CODCr where the spike value is the difference between median values for the two samples in the sample pair.
The assigned values for all parameters except Cl and SO4 are operationally defined and are consensus values based upon the median for method no. 62, 77 and 77A (CODCr), method no. 1 (NVOC), method no. 1 and 2 (TP), or method no. 1 and 2 (TSS), which are the methods required by the Danish EPA /5/. The assigned value for BOD7 is based upon standardised methods (method no. 1 - 4). A list of method identifi-cation numbers is found in the report to participants /1/. Assigned values for Cl and SO4 are consensus values for all laboratories based on the median. For BOD5 it was not possible to set an assigned value because only three laboratories had used a stand-ardised method.
2.3.2 Test of spike values A comparison was made (t-test, 95% confidence level) between the spike value and the difference in concentration between the two samples in the sample pair found from the laboratories’ results, see Appendix C. The test revealed a significant difference be-tween the two for CODCr and BOD7.
The difference for CODCr was significant and could not be attributed to specific meth-ods or other conditions. Furthermore, the difference had a significant influence on the general quality of analyses. It was therefore decided to change the spike value from the calculated value based on sample preparation to a value based on consensus between participating laboratories, i.e. the difference between the medians for sample A1 and B1.
For BOD7 the difference could be attributed to influence from laboratories using meth-ods other than the one prescribed by the Danish EPA. The test was repeated after ex-clusion of the results for method no. 9, and 52 and now showed no significant differ-ence. The spike value is therefore kept unchanged.
4
2.3.3 Test of assigned values The assigned value and the average of the results obtained from all laboratories were also compared (t-test, 95% confidence level), see Appendix D. The test showed no significant difference between the two and the control of assigned value at Eurofins confirmed the value (Appendix E).
5
3 HOMOGENEITY AND STABILITY OF SAMPLES
The homogeneity and stability of samples were tested using the following parameters as indicators:
CODCr Homogeneity test
TP Combined homogeneity and stability test
TSS Combined homogeneity and stability test
The results of control measurements are shown in Appendix F. The appendix also gives the results of the statistical evaluation of the control data. The data are analysed by analysis of variance (ANOVA) giving:
1. the standard deviation/variance for replicates (the contribution from analytical vari-ability),
2. the between bottle standard deviation/variance (the contribution from heterogenei-ty) and
3. the between days concentration difference (the contribution from instability).
Homogeneity is evaluated by comparing the between bottle variance to 0.3 * the standard deviation for evaluation of participants’ performance (0.3 ∙ σ�) specified by the Danish EPA /5/, whereas the stability is evaluated by comparing the concentration change of the samples to 0.3 ∙ σ�. This test ensures that heterogeneity and instability will not have negative influence on the evaluation of participant performance /6/.
The appendix also shows the standard deviation within and between laboratories from the proficiency test to allow comparison between tests performed and average quality from participating laboratories.
The tests for stability and homogeneity show that the samples are stable and homoge-neous.
6
4 CONCLUSION
The quality control performed, including test of sample stability and homogeneity as well as test of recovery of spike and assigned values, shows that the samples and their assigned values are suitable for testing the proficiency of the participating laboratories for all parameters. The results are also suitable for estimation of the general quality of analyses among all participating laboratories.
For BOD5 it was not possible to set an assigned value because too few laboratories have used a standardised method.
For BOD7 the participants could not recover the spike value. The difference between the calculated spike value and that found by the participants is small and the influence on evaluation of participant performance or estimation of general quality of analyses is insignificant.
7
5 REFERENCES
/1/ Eurofins A/S, Proficiency test SPIL-1 (2018), Report to participants, April 2018.
/2/ ISO 5725-2, Accuracy (trueness and precision) of measurement methods and re-sults – Part 2: Basic method for the determination of repeatability and reproduci-bility of a standard measurement method, 1994.
/3/ Spliid, H., Procedure and analysis of data for proficiency tests and environmental analyses, Report to Danish Environmental Protection Agency, 1994 (in Danish).
/4/ Eurofins A/S, Schedule for a proficiency test, document may be downloaded from www.eurofins.dk/proficiencytest.
/5/ Ministry of Environment regulation no. 1146 on quality criteria for environmental measurements, 24 October 2017 (in Danish).
/6/ ISO 13528, Statistical methods for use in proficiency testing by interlaboratory comparison, 2005.
8
A N N E X E S
9
ANNEX A LIST OF PARTICIPANTS
Laboratory Town Country AquaDjurs A/S Grenaa Denmark
Biofos A/S København K Denmark
Bjergmarken R/A, Fors Spildevand Roskilde Roskilde Denmark
BlueKolding A/S Kolding Denmark
CP Kelco, Spildevandslaboratoriet Ll. Skensved Denmark
Eurofins Miljø A/S Vejen Denmark
Faxe Forsyning Faxe Denmark
Fors Spildevand Holbæk Holbæk Denmark
Holstebro Centralrenseanlæg, Vestforsyning Spildevand
Holstebro Denmark
Kerteminde Forsyning - Spildevand A/S Kerteminde Denmark
Klarforsyning, Køge-Egnens Renseanlæg Køge Denmark
Melby Renseanlæg Liseleje Denmark
Nyborg Renseanlæg Nyborg Denmark
Næstved Central Renseanlæg, NK-Spildevand Næstved Denmark
Provas Haderslev Denmark
RGS Nordic A/S Skælskør Denmark
Ringkøbing-Skjern Forsyning A/S Skjern Denmark
Rønne Renseanlæg Rønne Denmark
Slagelse Renseanlæg (5 participants) Slagelse Denmark
Spildevandslaboratoriet (2 participants) Esbjerg Denmark
Svendborg Centralrenseanlæg Skårup Fyn Denmark
Vandmiljø Randers A/S Randers SØ Denmark
Vejle Renseanlæg Vejle Denmark
Macherey-Nagel GmbH & Co KG Düren Germany
Eurofins Environment Testing Norway AS Moss Norway
AB Borlänge Energi, Reningsverket Borlänge Sweden
Akzo Nobel Functional Chemicals AB, Cellulosic Specialties, QHSE
Örnsköldsvik Sweden
Arctic Paper Munkedals AB Munkedal Sweden
Campus Roslagen, Utvecklingscentrum för Vatten Norrtälje Sweden
Ernemar Laboratorium Oskarshamn Sweden
Fiskeby Board AB Norrköping Sweden
GRYAAB AB Göteborg Sweden
10
Gästrike Vatten AB Skutskär Sweden
Hallsta Pappersbruk Hallstavik Sweden
Holmen Paper AB, Bravikens Pappersbruk Norrköping Sweden
Iggesund Paperboard AB, Iggesunds Bruk, Cell & Miljölab
Iggesund Sweden
INOVYN Sweden AB Stenungsund Sweden
Kalmar Vatten AB, VA-lab Kalmar Sweden
Klippans Reningsverk Klippan Sweden
Kristianstad Kommun Kristianstad Sweden
Käppalaverket Lidingö Sweden
Laboratoriet vid Smedjeholms avolppsreningsverk Falkenberg Sweden
Ljungby Kommun, Avloppsreningsverket Ljungby Sweden
Mjölby Kommun Mjölby Sweden
Motala Kommun Motala Sweden
Nordic Sugar, Örtofta Sockerbruk Eslöv Sweden
Norrköping Vatten och Avfall AB, Laboratoriet Slottshagens Reningsverk
Norrköping Sweden
NSVA/Öresundsverket Helsingborg Sweden
Nynäshamn Kommun, VA-avd. Laboratoriet Nynäshamn Sweden
Preem AB Göteborg Göteborg Sweden
Preemraff Lysekil Lysekil Sweden
Reningsverket Aggerud Karlskoga Sweden
Rottneros Bruk AB Rottneros Sweden
Smurfit Kappa Piteå Piteå Sweden
St1 Refinery AB Göteborg Sweden
Stora Enso Paper AB Hyltebruk Sweden
Södra Cell AB Mönsterås Mönsterås Sweden
Södra Cell AB, Värö Väröbacka Sweden
Södra Cell Mörrum Mörrum Sweden
Tekniska förvaltningen, Verksamhetsstöd VA, Labo-ratoriet
Örebro Sweden
Uddebo Laboratorium Luleå Sweden
VA SYD Källby Avloppsreningsverk Malmö Sweden
VA SYD Sjölundalaboratoriet Malmö Sweden
VA SYD, Ellingelaboratoriet Malmö Sweden
Vallviks Bruk Vallvik Sweden
Västervik Miljö & Energi AB, Vattenlaboratoriet Västervik Sweden
11
ANNEX B SAMPLE PREPARATION
Stock solution Prepared from Concentration Concentrate A1 BOD
9.6010 g D-glucose 9.5996 g L-glutamic acid milli-Q water up to 13000 g
BOD: 1.034 g/kg
Concentrate B1 BOD
22.20 g D-glucose 22.20 g L-glutamic acid milli-Q water up to 24000 g
BOD: 1.295 g/kg
Concentrate A1 COD/NVOC
9.6010 g D-glucose 9.5996 g L-glutamic acid milli-Q water up to 13000 g
CODCr: 1.510 g/kg NVOC: 0.597 g/kg
Concentrate B1 COD/NVOC
22.20 g D-glucose 22.20 g L-glutamic acid milli-Q water up to 24000 g
CODCr: 1.892 g/kg NVOC: 0.747 g/kg
Stock TP 1.5006 g Na-B.glycerophosphate milli-Q water up to 1000.0 g
TP: 151.8 mg/kg
Stock Cl 10.003 g Sodium chloride (NaCl) milli-Q water up to 1000.0 g
Cl: 6.068 g/kg
Stock SO4 5.0057 g Sodium sulphate (Na2SO4) milli-Q water up to 1000.0 g
SO4: 3.385 g/kg
Stock TSS 15.03 g Microcrystalline cellulose milli-Q water up to 1000.0 g
TSS: 15.030 g/kg
12
Sample Sample prepared from CODCr mg/L O2
BOD (w. ATU) mg/L O2
NVOC mg/L C
TP mg/L P
Cl mg/L
SO4 mg/L
TSS mg/L
A1-BOD At the laboratory 5.00 mL of concen-trate A1 is diluted up to 2000.0 mL with filtered water from Vejen sewage treatment plant
b + 2.59
B1-BOD At the laboratory 5.00 mL of concen-trate B1 is diluted up to 2000.0 mL with filtered water from Vejen sewage treatment plant
b + 3.24
A1-COD/NVOC
At the laboratory 2.00 mL of concen-trate A1 is diluted up to 100.0 mL with filtered water from Vejen sewage treatment plant
a + 30.2 c + 11.9
B1-COD/NVOC
At the laboratory 2.00 mL of concen-trate B1 is diluted up to 100.0 mL with filtered water from Vejen sewage treatment plant
a + 37.8 c + 14.9
A2 100.03 g stock TP 500.0 g stock Cl 850.0 g stock SO4 Filtered water from Vejen sewage treatment plant up to 70.0 kg
d + 0.217 e + 43.3 f + 41.1
B2 60.04 g stock TP 150.01 g stock Cl 125.03 g stock SO4 Sample A2 up to 40.0 kg
0.992·
(d+0.217) + 0.228
0.992· (e + 43.3) +
22.8
0.992· ( f + 41.1) +
10.6
A3 At the laboratory 1000.0 mL of filtered water from Vejen sewage treatment plant is added to 3.0 mL stock TSS
g + 45.0
B3 At the laboratory 1000.0 mL of filtered water from Vejen sewage treatment plant is added to 2.5 mL stock TSS
g + 37.5
13
ANNEX C CONTROL OF SPIKE VALUES CODCr, mg/L 02 Control of differences within sample pairs
Laboratory Difference AB
1 -5.80 2 - 3 - 4 - 5 -0.30 6 -0.20 7 -0.60 8 - 9 4.00
10 1.80 11 -2.40 12 - 13 -1.30 14 11.80 UC 15 0.70 16 - 17 - 18 0.50 19 - 20 -0.50 21 - 22 -0.90 23 -1.40 24 -4.70 25 - 26 - 27 -8.70 28 - 29 - 30 -2.70 31 0.80 32 -2.20 33 - 34 -1.60 35 - 36 -1.10 37 -2.00 38 0.30 39 - 40 0.60 41 -1.20 42 -0.30 43 -0.50 44 -0.30 45 -0.80 46 - 47 - 48 -0.10 49 0.80 50 - 51 -
52A -1.10
Laboratory Difference AB
52B -0.20 53 -1.60 54 7.80 55 -1.30 UG 56 -0.50 57 - 58 -1.00 59 1.20 60 -1.60 61 2.10 62 0.30 63 -2.40 64 - 65 - 66 -0.45 67 0.90 68 0.30 69 6.30 70 -0.50 71 -2.30
No of labs., p 47 No of repl., n 2
d -0.49 s² 6.56 s 2.56
t = √p · (d/s) -1.3010 Sign. level, p(t) 0.1997 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
14
BOD5, mg/L 02 Control of differences within sample pairs
Laboratory Difference AB
1 - 2 - 3 - 4 - 5 - 6 -1.940 7 - 8 - 9 -2.070
10 - 11 - 12 - 13 - 14 -0.700 15 - 16 - 17 - 18 - 19 - 20 - 21 -0.450 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 0.000 37 - 38 - 39 - 40 - 41 0.730 42 - 43 -0.590 44 - 45 0.000 46 - 47 - 48 -0.500 49 - 50 - 51 -
52A - 52B -0.910
53 -1.930 54 - 55 -
Laboratory Difference AB
56 - 57 - 58 - 59 - 60 - 61 - 62 -0.170 63 - 64 - 65 - 66 0.000 67 - 68 - 69 - 70 0.510 71 -
No of labs., p 14 No of repl., n 2
d -0.573 s² 0.778 s 0.882
t = √p · (d/s) -2.4294 Sign. level, p(t) 0.0304 * * denotes that there is a significant difference (t-test, 5%-level) ** denotes that there is a significant difference (t-test, 1%-level) *** denotes that there is a significant difference (t-test, 0.1%-level) Difference for sample pair AB is significantly different from 0, and data should be corrected with the differ-ence (in spike value), during execution of Cochran's test.
15
BOD7, mg/L 02 Control of differences within sample pairs
Laboratory Difference AB
1 0.270 2 - 3 - 4 - 5 - 6 - 7 - 8 0.007 9 -
10 - 11 - 12 0.200 13 - 14 - 15 - 16 -0.400 17 0.450 18 2.710 UC 19 0.200 20 - 21 - 22 - 23 0.000 24 - 25 - 26 - 27 - 28 0.300 29 - 30 0.080 31 - 32 - 33 - 34 - 35 - 36 - 37 0.800 38 -0.010 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 0.300 47 - 48 - 49 - 50 0.140 51 0.000
52A - 52B -
53 - 54 0.330 55 -
Laboratory Difference AB
56 - 57 - 58 - 59 - 60 - 61 - 62 -0.360 63 0.080 64 - 65 - 66 - 67 0.000 68 - 69 - 70 - 71 0.300
No of labs., p 19 No of repl., n 2
d 0.141 s² 0.073 s 0.270
t = √p · (d/s) 2.2794 Sign. level, p(t) 0.0351 * * denotes that there is a significant difference (t-test, 5%-level) ** denotes that there is a significant difference (t-test, 1%-level) *** denotes that there is a significant difference (t-test, 0.1%-level) UC denotes a Cochran outlier Difference for sample pair AB is significantly different from 0, and data should be corrected with the differ-ence (in spike value), during execution of Cochran's test.
16
NVOC/TOC, mg/L C Control of differences within sample pairs
Laboratory Difference AB
1 -0.50 2 -0.20 3 -0.25 4 - 5 -0.20 6 - 7 1.16 8 -0.23 9 -
10 - 11 - 12 0.30 13 - 14 - 15 - 16 0.30 17 - 18 - 19 -0.68 20 - 21 2.00 22 -0.20 23 -0.15 24 0.60 25 0.44 26 0.28 27 - 28 0.20 29 0.20 30 - 31 - 32 -0.34 33 -0.60 34 - 35 0.30 36 0.10 37 0.43 38 - 39 0.20 40 - 41 - 42 - 43 0.60 44 - 45 -0.20 46 0.20 47 0.57 48 -0.20 49 -0.02 50 -0.10 51 -0.08
52A - 52B -
53 - 54 - 55 -
Laboratory Difference AB
56 - 57 1.78 UG 58 0.30 59 - 60 - 61 - 62 -0.73 63 -0.20 64 1.20 UG 65 -0.10 66 0.75 67 0.50 68 0.20 69 - 70 0.80 71 -
No of labs., p 39 No of repl., n 2
d 0.14 s² 0.27 s 0.52
t = √p · (d/s) 1.6831 Sign. level, p(t) 0.1005 No test statistics were found to be significant UG denotes a Grubbs outlier
17
Total phosphorus, mg/L P Control of differences within sample pairs
Laboratory Difference AB
1 0.020 2 -0.010 3 -0.026 4 -0.020 5 0.070 6 0.050 7 -0.030 8 0.060 9 -0.020
10 -0.020 11 -0.040 12 -0.040 UG 13 0.010 14 0.042 15 0.000 16 0.240 UC 17 0.046 18 -0.020 19 0.030 20 0.020 21 -0.003 22 -0.030 23 0.010 24 0.000 25 - 26 0.040 27 0.000 28 0.010 29 -0.020 30 - 31 0.010 32 0.018 33 -0.030 34 -0.000 35 -0.030 36 0.040 37 0.160 UC 38 0.054 39 -0.020 40 0.040 41 -0.020 42 0.080 43 -0.080 44 -0.020 45 -0.010 46 0.000 47 0.030 48 -0.050 49 0.430 UC 50 0.020 51 -0.026
52A 0.010 52B 0.000
53 0.040 54 0.017 55 -0.000
Laboratory Difference AB
56 -0.000 57 - 58 -0.010 59 -0.017 60 -0.020 61 -0.030 62 -0.050 63 -0.040 64 0.050 65 -0.160 UC 66 0.180 UC 67 0.000 68 0.020 69 0.020 70 0.070 71 0.014
No of labs., p 63 No of repl., n 2
d 0.004 s² 0.001 s 0.033
t = √p · (d/s) 0.9545 Sign. level, p(t) 0.3435 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
18
Chloride, mg/L Control of differences within sample pairs
Laboratory Difference AB
1 - 2 10.7 3 - 4 - 5 -5.0 6 -6.0 7 - 8 - 9 -
10 -20.0 UG 11 -0.5 12 - 13 - 14 -6.0 15 -6.0 16 - 17 - 18 -4.0 19 1.8 20 -14.8 UG 21 2.0 22 - 23 - 24 - 25 1.4 26 - 27 - 28 - 29 -27.0 UC 30 - 31 -1.0 32 - 33 - 34 3.4 35 - 36 - 37 - 38 - 39 - 40 1.0 41 -12.0 42 -6.0 43 -2.0 44 - 45 -3.0 46 - 47 - 48 0.0 49 -1.0 50 - 51 -
52A -5.0 52B -4.0
53 1.0 54 - 55 -
Laboratory Difference AB
56 12.0 57 - 58 1.0 59 0.2 60 -39.0 UC 61 - 62 2.3 63 - 64 - 65 1.0 66 -2.5 67 - 68 2.0 69 -11.0 70 -0.7 71 1.7
No of labs., p 32 No of repl., n 2
d -1.1 s² 24.9 s 5.0
t = √p · (d/s) -1.2120 Sign. level, p(t) 0.2347 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
19
Sulphate, mg/L Control of differences within sample pairs
Laboratory Difference AB
1 - 2 0.80 3 - 4 - 5 -0.70 6 2.30 7 - 8 - 9 -
10 - 11 - 12 - 13 - 14 0.60 15 - 16 - 17 - 18 - 19 - 20 -1.20 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 0.10 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 -2.70 41 - 42 - 43 - 44 - 45 3.60 46 - 47 - 48 - 49 3.20 50 - 51 -
52A - 52B 0.10
53 -2.10 54 - 55 -
Laboratory Difference AB
56 - 57 - 58 0.00 59 - 60 - 61 - 62 0.72 63 - 64 - 65 0.00 66 - 67 - 68 -9.50 69 10.90 70 0.30 71 -
No of labs., p 17 No of repl., n 2
d 0.38 s² 15.65 s 3.96
t = √p · (d/s) 0.3936 Sign. level, p(t) 0.6991 No test statistics were found to be significant
20
Total suspended solids, mg/L Control of differences within sample pairs
Laboratory Difference AB
1 1.70 2 0.20 3 -1.50 4 - 5 -13.10 UC 6 -0.90 7 1.50 8 -3.00 9 -0.50
10 1.90 UG 11 - 12 -3.00 13 - 14 -1.40 15 0.80 16 -0.30 17 0.61 18 -0.40 19 0.30 20 -5.50 21 - 22 2.80 23 -0.20 24 -0.50 25 - 26 -0.80 27 -3.50 28 0.00 29 -1.50 30 - 31 -0.80 32 -0.10 33 -1.60 34 -0.40 35 -0.30 36 -1.50 37 -2.50 38 2.10 39 -1.20 40 - 41 -0.80 42 -2.50
Laboratory Difference AB
43 3.10 44 - 45 -1.50 46 1.30 47 0.00 48 -0.90 49 0.80 50 -0.40 51 0.60
52A - 52B 0.30
53 3.30 54 2.50 55 0.90 56 -0.20 57 0.78 58 - 59 -2.48 60 2.60 61 -0.40 62 0.55 63 0.90 64 1.01 65 0.10 66 -6.30 67 -0.50 68 - 69 0.60 70 -0.40 71 0.90
No of labs., p 59 No of repl., n 2
d -0.30 s² 3.34 s 1.83
t = √p · (d/s) -1.2495 Sign. level, p(t) 0.2165 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
21
ANNEX D CONTROL OF RECOVERY CODCr, mg/L 02 Control of recovery, average of results
Laboratory Sample pair AB
1 55.40 2 - 3 - 4 - 5 44.25 6 44.70 7 53.80 8 - 9 33.00
10 51.80 11 45.60 12 - 13 48.35 14 40.40 UC 15 42.05 16 - 17 - 18 43.45 19 - 20 42.35 21 - 22 48.65 23 53.25 24 47.65 25 - 26 - 27 56.65 28 - 29 - 30 48.75 31 42.90 32 51.20 33 - 34 51.55 35 - 36 45.75 37 50.00 38 49.75 39 - 40 44.60 41 44.80 42 43.05 43 44.45 44 43.15 45 43.70 46 - 47 - 48 44.55 49 51.20 50 - 51 -
52A 44.35 52B 41.90
Laboratory Sample pair AB
53 44.30 54 57.90 55 88.35 UG 56 50.95 57 - 58 48.50 59 48.90 60 45.70 61 55.55 62 44.85 63 50.10 64 - 65 - 66 43.98 67 52.05 68 45.75 69 43.55 70 50.25 71 45.05
No of labs., p 47 No of repl., n 2
m 47.32 s² 22.44 s 4.74
Assigned value, µ 48 Recovery, % 98.6 t = √p · (m-µ)/s -0.9861 Sign. level, p(t) 0.3292 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
22
BOD5, mg/L 02 Control of recovery, average of results
Laboratory Sample pair AB
1 - 2 - 3 - 4 - 5 - 6 6.760 7 - 8 - 9 3.505
10 - 11 - 12 - 13 - 14 3.990 15 - 16 - 17 - 18 - 19 - 20 - 21 4.095 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 5.600 37 - 38 - 39 - 40 - 41 2.255 42 - 43 4.105 44 - 45 1.850 46 - 47 - 48 3.150 49 - 50 - 51 -
52A - 52B 5.145
53 5.145 54 - 55 -
Laboratory Sample pair AB
56 - 57 - 58 - 59 - 60 - 61 - 62 4.745 63 - 64 - 65 - 66 5.000 67 - 68 - 69 3.580 70 3.405 71 -
No of labs., p 14 No of repl., n 2
m 4.196 s² 1.756 s 1.325
Assigned value, µ - Recovery, % - t = √p · (m-µ)/s - Sign. level, p(t) - No test statistics were found to be significant
23
BOD7, mg/L 02 Control of recovery, average of results
Laboratory Sample pair AB
1 3.485 2 - 3 - 4 - 5 - 6 - 7 - 8 4.155 9 -
10 - 11 - 12 4.000 13 - 14 - 15 - 16 3.400 17 4.105 18 7.875 UC 19 3.700 20 - 21 - 22 - 23 3.800 24 - 25 - 26 - 27 - 28 4.450 29 - 30 4.790 31 - 32 - 33 - 34 - 35 - 36 - 37 3.400 38 4.815 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 4.160 47 - 48 - 49 - 50 4.370 51 4.200
52A - 52B -
53 - 54 3.875 55 -
Laboratory Sample pair AB
56 - 57 - 58 - 59 - 60 - 61 - 62 5.090 63 4.540 64 - 65 - 66 - 67 4.300 68 - 69 - 70 - 71 3.500
No of labs., p 19 No of repl., n 2
m 4.112 s² 0.247 s 0.497
Assigned value, µ 4.2 Recovery, % 97.9 t = √p · (m-µ)/s -0.7694 Sign. level, p(t) 0.4516 No test statistics were found to be significant UC denotes a Cochran outlier
24
NVOC/TOC, mg/L C Control of recovery, average of results
Laboratory Sample pair AB
1 17.25 2 19.90 3 18.30 4 - 5 19.00 6 - 7 18.31 8 18.55 9 -
10 - 11 - 12 17.05 13 - 14 - 15 - 16 18.85 17 - 18 - 19 18.27 20 - 21 15.94 22 20.20 23 18.68 24 18.10 25 19.35 26 19.94 27 - 28 18.90 29 20.00 30 - 31 - 32 18.28 33 20.90 34 - 35 19.75 36 19.35 37 19.55 38 - 39 19.50 40 - 41 - 42 - 43 20.70 44 - 45 19.00 46 19.30 47 20.05 48 20.00 49 20.69 50 18.75 51 18.51
52A - 52B -
53 - 54 - 55 -
Laboratory Sample pair AB
56 - 57 8.27 UG 58 19.25 59 - 60 - 61 - 62 20.45 63 18.30 64 13.30 UG 65 17.75 66 19.32 67 19.65 68 20.50 69 - 70 17.40 71 -
No of labs., p 39 No of repl., n 2
m 19.07 s² 1.21 s 1.10
Assigned value, µ 18.9 Recovery, % 100.9 t = √p · (m-µ)/s 0.9357 Sign. level, p(t) 0.3553 No test statistics were found to be significant UG denotes a Grubbs outlier
25
Total phosphorus, mg/L P Control of recovery, average of results
Laboratory Sample pair AB
1 1.130 2 1.155 3 1.073 4 1.100 5 1.125 6 1.175 7 1.165 8 1.066 9 1.060
10 1.110 11 1.210 12 1.440 UG 13 1.205 14 1.065 15 1.200 16 1.040 UC 17 1.099 18 1.180 19 1.135 20 1.160 21 1.131 22 1.115 23 1.173 24 1.170 25 - 26 1.210 27 1.160 28 1.055 29 1.150 30 - 31 1.205 32 1.147 33 1.125 34 1.140 35 1.095 36 1.120 37 1.150 UC 38 1.146 39 1.150 40 1.140 41 1.170 42 1.120 43 1.160 44 1.080 45 1.155 46 1.160 47 1.205 48 1.165 49 1.135 UC 50 1.190 51 1.102
52A 1.145 52B 1.180
53 1.190 54 1.098 55 1.130
Laboratory Sample pair AB
56 1.150 57 - 58 1.135 59 1.176 60 1.200 61 1.105 62 1.265 63 1.250 64 1.105 65 1.130 UC 66 1.330 UC 67 1.030 68 1.100 69 1.210 70 0.985 71 1.144
No of labs., p 63 No of repl., n 2
m 1.142 s² 0.003 s 0.051
Assigned value, µ 1.14 Recovery, % 100.2 t = √p · (m-µ)/s 0.3201 Sign. level, p(t) 0.7500 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
26
Chloride, mg/L Control of recovery, average of results
Laboratory Sample pair AB
1 - 2 123.8 3 - 4 - 5 113.5 6 128.0 7 - 8 - 9 -
10 174.0 UG 11 137.3 12 - 13 - 14 132.0 15 128.0 16 - 17 - 18 123.0 19 132.9 20 80.6 UG 21 132.0 22 - 23 - 24 - 25 134.0 26 - 27 - 28 - 29 184.5 UC 30 - 31 122.5 32 - 33 - 34 131.3 35 - 36 - 37 - 38 - 39 - 40 110.5 41 120.0 42 122.0 43 133.0 44 - 45 130.5 46 - 47 - 48 132.0 49 120.5 50 - 51 -
52A 108.5 52B 123.0
53 132.5 54 - 55 -
Laboratory Sample pair AB
56 131.0 57 - 58 128.0 59 133.7 60 127.5 UC 61 - 62 127.0 63 - 64 - 65 129.5 66 135.8 67 - 68 141.0 69 130.5 70 133.4 71 133.9
No of labs., p 32 No of repl., n 2
m 128.0 s² 56.5 s 7.5
Assigned value, µ 130 Recovery, % 98.4 t = √p · (m-µ)/s -1.5408 Sign. level, p(t) 0.1335 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
27
Sulphate, mg/L Control of recovery, average of results
Laboratory Sample pair AB
1 - 2 68.20 3 - 4 - 5 71.55 6 74.75 7 - 8 - 9 -
10 - 11 - 12 - 13 - 14 74.40 15 - 16 - 17 - 18 - 19 - 20 84.10 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 65.25 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 77.05 41 - 42 - 43 - 44 - 45 69.50 46 - 47 - 48 - 49 68.40 50 - 51 -
52A - 52B 79.45
53 74.65 54 - 55 -
Laboratory Sample pair AB
56 - 57 - 58 75.00 59 - 60 - 61 - 62 72.07 63 - 64 - 65 69.60 66 - 67 - 68 64.55 69 65.05 70 71.45 71 -
No of labs., p 17 No of repl., n 2
m 72.06 s² 27.87 s 5.28
Assigned value, µ 72 Recovery, % 100.1 t = √p · (m-µ)/s 0.0469 Sign. level, p(t) 0.9632 No test statistics were found to be significant
28
Total suspended solids, mg/L Control of recovery, average of results
Laboratory Sample pair AB
1 36.85 2 35.20 3 34.85 4 - 5 28.85 UC 6 36.05 7 35.75 8 38.30 9 39.75
10 18.25 UG 11 - 12 34.00 13 - 14 36.40 15 36.20 16 37.05 17 33.41 18 35.00 19 36.45 20 34.25 21 - 22 37.70 23 36.50 24 35.75 25 - 26 36.30 27 37.75 28 37.60 29 37.75 30 - 31 36.50 32 36.85 33 36.20 34 36.30 35 36.45 36 36.35 37 35.25 38 37.45 39 33.70 40 - 41 35.20 42 32.95 43 32.55 44 - 45 35.25 46 35.75 47 35.70 48 32.75 49 36.90 50 36.20 51 36.70
52A - 52B 38.55
53 33.65 54 34.85 55 34.65
Laboratory Sample pair AB
56 33.90 57 34.31 58 - 59 35.99 60 37.90 61 36.10 62 35.91 63 36.15 64 37.11 65 36.65 66 33.45 67 39.05 68 - 69 36.80 70 36.30 71 36.25
No of labs., p 59 No of repl., n 2
m 35.96 s² 2.39 s 1.54
Assigned value, µ 36.2 Recovery, % 99.3 t = √p · (m-µ)/s -1.2107 Sign. level, p(t) 0.2309 No test statistics were found to be significant UC denotes a Cochran outlier UG denotes a Grubbs outlier
29
ANNEX E CONCENTRATION LEVEL
Parameter Unit Sample Bottle no. I II Bottle Sample Assigned Spike
Average Average value Measured Assigned
COD mg/L O2 A1 91-8 43.5 43.8 43.65 43.72 48 6 6
52-32 44.0 44.1 44.05
13-58 43.8 43.1 43.45
B1 8-20 49.4 49.2 49.30 49.63 54
48-41 50.0 48.8 49.40
71-53 50.1 50.3 50.20
Total phosphorus mg/L P A2 11 1.18 1.18 1.18 1.17 1.14 0.22 0.22
69 1.12 1.15 1.14
35 1.20 1.18 1.19
B2 12 1.40 1.41 1.41 1.39 1.36
56 1.40 1.39 1.40
88 1.36 1.38 1.37
Chloride mg/L A2 11 117 114 115.5 112.3 130 19 22
69 114 115 114.5
35 106 108 107.0
B2 12 131 131 131.0 131.0 152
56 132 130 131.0
88 131 131 131.0
Sulphate mg/L A2 11 63.1 59.7 61.40 61.7 72 11 10
69 60.9 63.0 61.95
35 61.6 61.8 61.70
B2 12 74.2 70.7 72.45 72.5 82
56 71.1 72.1 71.60
88 71.8 75.3 73.55
Total suspended mg/L A3 27-19 44.2
44.2 44.9 43.7 -7.8 -7.5 solids
50-38 46.8
46.8
66,52 43.7
43.7
B3 9-11 36.9
36.9 37.1 36.2
54-41 37.5
37.5
84-68 36.8
36.8
30
ANNEX F HOMOGENEITY AND STABILITY
PT: SPIL-1 Parameter: TP
Unit: mg/L P
Sigma: 0.075
Responsible for tests: IRL
Homogeneity test Date: 2018-02-28
Stability test Date: 2018-03-15
Sample x(a) x(b) average sd sd^2
Sample x(a) x(b) B2-9 1.43 1.38 1.4 0.035 0.001
B2-12 1.40 1.41
B2-14 1.45 1.40 1.4 0.035 0.00
B2-56 1.40 1.39 B2-23 1.40 1.40 1.4 0.000 0.000
B2-88 1.36 1.38
B2-27 1.40 1.39 1.4 0.007 0.000
B2-36 1.39 1.38 1.4 0.007 0.000
B2-48 1.34 1.3
For stability B2-59 1.36 1.36 1.4 0.000 0.000
General average (y): 1.39
B2-70 1.44 1.39 1.4 0.035 0.001
/x-y/ =
0.0045833 B2-78 1.39 1.39 1.4 0.000 0.000
B2-81 1.40 1.41 1.4 0.007 0.000
B2-85 1.39 1.40 1.4 0.007 0.000
B2-94 1.41 1.43 1.4 0.014 0.000 Conclusions
ss = 0.020 0.3*sigma= 0.02
For homogeneity
/x-y/ = 0.0045833
General average (x) 1.39
Sample average sd (sx) 0.024
Within-sample sd (sw): 0.019
Between-samples sd (ss): 0.0201
Homogeneity: Is ss < 0.3*sigma?
SL in the Proficiency Test: 0.049
YES
SR in the Proficiency Test: 0.054
Stability: /x-y/ < 0.3*sigma?
YES
31
PT: SPIL-1
Parameter: TSS
Unit: mg/L
Sigma: 3.6
Responsible for tests: IRL
Homogeneity test Date: 2018-02-28
Stability test Date: 2018-03-15
Sample x(a) x(b) average sd sd^2
Sample x(a) x(b) B3-14-77 36.8 36.8
B3-9-11 36.9
B3-20-6 36.7 36.7
B3-54-41 37.5 B3-21-58 35.4 35.4
B3-84-68 36.8
B3-31-60 36.8 36.8
B3-40-24 36.6 36.6
B3-41-30
For stability B3-51-13 37.9 37.9
General average (y): 37.066667
B3-57-79 37.1 37.1
/x-y/ =
0.1757576 B3-72-67 37.2 37.2
B3-74-31 37.1 37.1
B3-83-86 37.1 37.1
B3-85-42 37.1 37.1 Conclusions
ss = 0.60 0.3*sigma= 1.08
For homogeneity
/x-y/ = 0.1757576
General average (x) 36.9
Sample average sd (sx) 0.604
Within-sample sd (sw):
Between-samples sd (ss): 0.604
Homogeneity: Is ss < 0.3*sigma?
SL in the Proficiency Test: 1.25
YES
SR in the Proficiency Test: 1.79
Stability: /x-y/ < 0.3*sigma?
YES